Image stitching is a process of blending together two or more images to form a single image. For example, images from a single camera are sometimes stitched to form a single panoramic image of a scene. Also, multiple cameras are often employed to capture multiple images or videos which are stitched together to form a panoramic image or video of a scene (e.g. Cinerama or “widescreen” movies). When multiple cameras are employed, the cameras are generally mechanically indexed with one another so as to create a continuous scene across transitions between cameras.
Typically, the cameras are also adjusted so as to have the same settings, such as exposure settings, for example. Nevertheless, there a generally differences in intensity between acquired images due to a variety of factors such as, for example, inherent differences in tolerances of cameras and changes in lighting conditions over time. Consequently, when stitched together, the resulting panoramic image will often exhibit distinct edges at the boundaries of the individual images due to the differing intensities. This can be particularly troublesome for panoramic movies/videos, where intensities can vary between images of a same frame and between images of different frames, resulting in a “flickering” effect when the movie is viewed. To reduce such effects, the intensities of adjacent images are generally adjusted during the stitching process so that the images blend together more seamlessly.
Standard image blending techniques typically require an overlap area between two images. However, in order to obtain the largest field of view possible, multiple camera systems are often mechanically indexed to minimize or eliminate overlap between images. In such instances, images may have very little overlap or merely abut one another with no overlap at all.